Fantasy author Jim C. Hines raised this question on his blog recently and it got me thinking about it. In particular, is it appropriate for an author to share a negative review of another author's work? Is there a conflict of interest? What do you think?
This question is of particular interest to me because I am a published author and a reviewer. I've only had a few short stories published, so I'm not the sort of author Hines is talking about (ie. somebody who actually makes a living out of it) but I'd like to be one day so I'm curious about other people's thoughts on this topic.
I agree with Hines that there would certain practical problems for the author, like angering publishers, but ethically I think it's okay. It's just the author's opinion of someone else's work. I know some people think you should just refrain from reviewing books you really hate, and a negative review is might be less useful to reader than a recommendation, but I can understand wanting to let rip if a really awful book upset you or made you angry.
I think that as long as you are open about the fact that you are an author (obviously if you're famous this will apparent!) and are therefore critiquing your "competition" then it would be fine to review another author's work. I do think that if you are offering a negative review of someone who is your competition then you will be called upon to provide VERY robust reasoning and it could put other people off your work if they are left wondering if you are simply being vindictive.
I guess I don't see an ethical issue but you'd probably want to tread carefully!